RU2763053C1 - Arrangement of spawning mounds for laying brook trout eggs - Google Patents

Abstract

FIELD: fish artificial breeding.

SUBSTANCE: invention relates to the artificial breeding of fish and can be used for the reproduction of stocks of brook trout. Spawning mounds are arranged by hand, three-layered at a distance from each other in spring streams. The first layer is made of river gravel, the second layer is made of light fascines, which form a nest for laying and incubating brook trout eggs. The third layer of the hillock is made of large river pebbles, while light fascines are made in the form of a bundle of ripe reeds with a diameter of 7-10 cm. Caviar is laid in the nest of each hillock using a transparent plastic 1.5-liter bottle with a cut-off bottom, finely perforated sides and a wide neck.

EFFECT: increased efficiency of artificially arranged brook trout spawning grounds.

2 cl, 4 dwg

Description

The invention relates to fisheries, more precisely to artificial breeding of salmonids, and can be used for reproduction of stocks of brook trout Salmo trutta caspius Kessler (morpha fario).

There is a known method of breeding river trout fry (larvae) in trout factories and releasing them into rivers for reproduction of natural reserves of trout [1]. The main disadvantage of this technique is that it is characterized by low efficiency, because of the young, immature, defenseless fry released at an early age in natural conditions full of danger, only an insignificant part (less than 1%) survives to the commercial size.

Known artificial nests-incubators, installed in rivers for incubation of eggs, which are installed on the open from ice rapids-rolling sections of rivers at the end of March [2]. Such devices are not quite suitable for mountain brook trout. Artificial nests-incubators during the period of their technological production are costly, their installation in spawning grounds is laborious and time-consuming to install, they are ineffective in the conditions of small rivers with spring feeding, where trout live and breed.

The purpose of the invention is to improve the efficiency of artificial spawning grounds for brook trout.

This goal is achieved by the fact that in the arrangement of spawning mounds containing artificial nests for incubating brook trout eggs, the spawning mounds are arranged manually, three-layer at a distance from each other in spring streams, the first layer is made of river gravel, the second layer is made of light fascines, forming a nest for laying and incubating brook trout eggs, the third layer of the mound is made of large river pebbles, while the light fascines are made in the form of a bundle of ripe reeds, 7-10 cm in diameter, and the eggs are laid in the nest of each mound using a transparent plastic 1.5-liter bottle with a cut-off bottom, with finely perforated sides and a wide neck. At the same time, artificially erected spawning hillocks with eggs incubation nests create the most optimal conditions for the restoration and increase of natural stocks of brook trout.

FIG. 1 shows the core section of the stream with artificially equipped spawning hillocks in a section along its bed; in fig. 2 - flexible mattress made of light fascines, forming a nest for caviar; in fig. 3 - light fascina made of dry reeds; in fig. 4 is a diagram of laying brook trout eggs in a spawning hillock using a plastic bottle with caviar.

Spawning mounds 1 of brook trout consist of three layers: the first layer is made of river gravel 2, the second layer is made of light fascines 3, interconnected in the form of a flexible mattress, forming a nest 4 for laying and incubating eggs 5 of brook trout, the third layer of the mound is made from large river pebbles 6. Light fascines 3 are made in the form of a bunch (tied in three places) of ripe reeds, 7-10 cm in diameter. 9 and wide neck 10.

Spawning mounds for laying brook trout eggs are constructed as follows.

First, on the spawning site of mountain streams, the places for laying artificially equipped mounds 1 are outlined. The distance between the hillocks should be at least 1.5 m, this distance can be from 1.5 to 5 m or more, depending on the hydrological and geomorphological conditions of a particular section of the river, or spring stream. The required volume of ripe reeds is collected and brought to the place where the spawning mounds 1 are laid. Then, light fascines 3 are made in the form of bundles (tied in three places) with a diameter of 7-10 cm and a length of 120-150 cm.

Then, from light fascines 3 (laid on a flat plane close to each other in one row), flexible mattresses are tied - 4 nests for caviar 5 of brook trout. In this order, the required number of flexible mattresses, 7-10 cm thick, corresponding to the diameter of light fascines 3. This thickness of flexible mattresses, used as nests for eggs of 5 brook trout, is most acceptable for incubating their eggs and further development of larvae and fry. After that, manually using a pitchfork and a rake, the first layers of river gravel 2 are collected at the places where mounds 1 were laid, the thickness of the first layer of pebble 2 of each hillock is approximately 10-12 cm. On top of the pebble layer 2, a second layer is laid - a flexible mattress made of light fascines 3, forming a nest 4 for laying eggs 5, at the same time the second layer from above is loaded with large river pebbles 6 (approximately of the same size - 40-60 mm), forming a third layer, 8-10 cm thick.In this order, build the required number of spawning mounds 1 , and the number of hillocks in one section of a mountain stream can be 3-5 or more. Further, artificial fertilization of brook trout eggs is carried out in fish hatcheries "by dry method". The transportation of caviar from the fish factory to a spring brook or river is carried out by light vehicles in a foam thermos. Eggs 5 are laid in nests 4 of knolls 1 in small portions (up to hundreds of eggs) using a transparent plastic one and a half liter bottle 7 with a cut bottom 8, with finely perforated sides 9 and a wide neck 10. First, a portion of caviar is placed in bottle 7 from the side of the cut bottom 8. Next, the bottle with caviar is gently lowered into the water upside down. At the same time, its neck 10 is covered with a hand (to prevent caviar from falling out of it), then, immersing the bottle to the very top of the mound 1, the hand is removed, and the neck 10 is stuck into the pebbles to the second layer (nest 4) of light fascines 3. Through fine perforation 9, water flows into the bottle 7. After the caviar roiled in the bottle settles in its lower part, the bottle 7 is slowly raised and the caviar 4 is poured onto a flexible mattress - into the nest 4 from the lungs of fascina 3, at the same time it is sprinkled on top with large and uniform pebbles 6.

Thus, spawning mounds are built and eggs (at the “eye” stage) of brook trout are laid in nests 4 of all prepared spawning mounds 1.

Spawning mounds, arranged in the mountainous areas of spring streams, with laid eggs of brook trout, work as follows.

In the spring period, fertilized eggs 5 (at the "eye" stage) in the nests of mounds 1 develop rapidly and after a certain time larvae hatch from it. This is facilitated by light fascines from the reeds, in the straws of which air is held for a long time, which maintains the saturation of water in the nests with oxygen and creates normal conditions for the incubation of eggs 5. The stones of the upper layer protect the eggs from being carried away by the water flow, from increased insolation and predators, for this depth egg laying must be kept within 5-10 cm from the ground surface of mounds 1. At first, the larvae feed on the supply of nutrients from the yolk sac and small larvae of secondary water insects (coastal aquatic plants). Ripe reeds, from which light fascines 3 are made, are nutritious natural material for zoobenthos forms living in river water. Due to this, brook trout fry grow from the larvae, which swim out from under the rocky-pebble substrate into the aquatic environment of mounds 1. The stones of the upper layer of spawning mounds 1 help them to hold on (hide between stones), protect themselves from predatory invertebrates and vertebrates. Then fry of trout adapt to the conditions of a mountain stream and grow up to adults (broodstock).

Thus, the proposed arrangement of spawning mounds from rocky soil and with nests for incubation of eggs creates favorable conditions for individual development and restoration of stocks of brook trout.

Spawning mounds, three-layer with nests for incubation of brook trout eggs, can be most effectively used in mountainous and foothill areas of spring rivers and streams.

Literature

1.ribovodstvo.com/books/item/f00/s00/z0000008/st023.shtml

2. RF patent 2386248. Method for incubating eggs in artificial nests-incubators installed in rivers. / Pavlov D.S., Skorobogatov M.A. et al. Bull. No. 11 publ. 20.04.2010.

Claims (2)

1. Arrangement of spawning mounds for laying brook trout eggs, containing artificial nests for incubating brook trout eggs, characterized in that the spawning mounds are arranged manually, three-layer at a distance from each other in spring streams, the first layer is made of river gravel, the second layer is made of light fascines, forming a nest for laying and incubating brook trout eggs, the third layer of the mound is made of large river pebbles, while the light fascines are made in the form of a bundle of ripe reeds with a diameter of 7-10 cm, and the eggs are laid in the nest of each mound using transparent plastic one and a half liter bottle with a cut-off bottom, with finely perforated sides and a wide neck. 2. Arrangement of spawning mounds for laying brook trout eggs according to claim 1, characterized in that artificially erected spawning mounds with eggs incubation nests create the most optimal conditions for the restoration and increase of natural stocks of brook trout.

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